Monitoring volcanoes in Iceland and their current status Sara Barsotti Coordinator for Volcanic Hazards, [email protected] Overview • Volcanoes and volcanic eruption styles in Iceland • Monitoring volcanoes and volcanic eruptions • Current status at • Hekla • Katla • Bárðarbunga • Grímsvötn • Öræfajökull 2 The catalogue of Icelandic Volcanoes – icelandicvolcanoes.is It includes historical activity, current seismicity, possible hazards and scenarios, GIS-based map layers to visualize eruption product extensions (lava flows, ash deposits) – ICAO project 3 Explosive vs. Effusive eruption Eyjafjallajökull 2010 Bárðarbunga - Holuhraun 2014-2015 • Volcanic cloud (possibly up to • Lava flow the stratosphere) • Volcanic gas into the • Tephra fallout atmosphere (hardly higher • Lightning than the tropopause) • Floods (if from ice-capped volcano) • Pyroclastic flows 4 Volcanic ash hazards from Icelandic volcanoes All these volcanoes have volcanic ash as one of the principal hazards 5 Eruption in Iceland since 1913 Year Volcano VEI Note Stile of activity 2014 Holuhraun (Bárðarbunga) 1 Effusive 2011 Grímsvötn 4 Ice Explosive 2010 Eyjafjallajökull 3 Ice Explosive/effusive 2004 Grímsvötn 3 Ice Explosive 2000 Hekla 3 Effusive/explosive 1998 Grímsvötn 3 Ice Explosive 1996 Gjálp (Grímsvötn) 3 Ice Subglacial-explosive 1991 Hekla 3 Effusive/explosive 1983 Grímsvötn 2 Ice Explosive 1980-81 Hekla 3 Effusive/explosive 1975-84 Krafla fires (9 eruptions) 1 Effusive 1973 Heimaey 2 Effusive/explosive 1970 Hekla 3 Effusive/explosive Instrumental monitoring 1963-67 Surtsey 3 Ocean Explosive/effusive 1961 Askja 2 Effusive 1947-48 Hekla 4 Effusive/explosive 1938 Gjálp (Grímsvötn) - Ice Subglacial 1934 Grímsvötn 3 Ice Explosive 1922-29 Askja (5-6 eruptions) 2 (lake) Effusive/explosive 1922 Grímsvötn 3 Ice Explosive 1918 Katla 4 Ice Explosive 1913 Hekla 1 Effusive No instrumental monitoring Frequencies of eruptive styles Volcano Purely explosive Purely effusive (or with explosive component) Hekla 82% 18% Katla 97% 3% Bárðarbunga 90% 10% Grímsvötn 95% 5% 7 The size of an explosive eruption: the VEI Volcanic Explosivity Index: Erupted volume of tephra is often used as a proxy for magnitude for explosive eruptions. Katla 934, Hekla 1104, Askja 1875 Öræfajökull 1362, BB-Veiðivötn 1477 8 The role of the Icelandic Meteorological Office The main purpose of IMO is to contribute towards increased security and efficiency in society by: Monitoring, analysing, interpreting, informing, giving advice and counsel, providing warnings and forecasts and where possible, predicting natural processes and natural hazards. Issuing public and aviation alerts about impending natural hazards, such as volcanic ash, extreme weather and flooding Water, snow, Atmosphere glaciers Geophysical processes Earth Ocean IMO and IVO • IVO is the Icelandic Volcano Observatory and it coexists within IMO • Integration of interpretations and multidisciplinary investigation • Fast and effective communication Operational response IMO designes and follows contingency plans for all monitored natural hazards and for different field teams. Regarding volcanoes, our main stakeholders are: CIVIL PROTECTION and GENERAL AVIATION sector (L-VAAC, ISAVIA) PUBLIC triggered by phone calls and IMO‘s web- triggered by phone calls site 1.Possible scenarios and evolution 1.Onset of an eruption of the ongoing situation 2.Plume height and characteristics 2.Hazards assessment of ash cloud 3.Forecasts of ash/gas dispersal 3.Temporal variability of eruption and fallout in the country style and intensity 4.Scientific support for risk mitigation actions Volcano Observatory‘s tasks • To detect and interpret signs of unrest that might lead to an eruption • needs long-term monitoring data to identify a background level as well as real-time monitoring to see changes on small time scales • To assess the possible volcanic hazards and their temporal evolution in case of an eruption • needs a background knowledge of historical activity to identify possible hazards as well as real-time monitoring to follow the ongoin event and variations in intensity, spatial distribution of the hazard • To timely and properly communicate to stakeholder • needs a response plan and clear indication on the vital information that are needed by the users 20/02/2020 12 Monitoring setup • Multi-parametric monitoring built on three main pillars: Geophysics and Atmosphere and Remote sensing and geochemistry acoustic satellite 13 Monitoring setup • Multi-parametric monitoring built on three main pillars: Geophysics and Atmosphere and Remote sensing and geochemistry acoustic satellite 14 Monitoring setup • Multi-parametric monitoring built on three main pillars: Geophysics and Atmosphere and Remote sensing and geochemistry acoustic satellite 15 Monitoring and Research: geophysical and geochemical monitoring for forecasting purposes • ~ 70 seismic stations • 145 hydrological gauging stations • 70 GPS • 5 strain-meter stations • 3 MultiGas devices • 1+(6) continuous DOAS (SO2) • Conductivity sensors (glacial outlet rivers) • InSAR • Satellite acquisition (e.g. Landsat, Sentinel) • FTIR • Water chemistry sensors (dissolved CO2) Monitoring and Research: ash cloud detection and investigation during an eruption • C-band weather radar close to Keflavík airport since Jan 1991 • has detected 7 eruptions • C-band weather radar in East Iceland, operational since April 2012 • 2 X-band mobile radars • 2 Lidars (one mobile) • 7-ceilometers network • 5 infrasound arrays • Mobile radio-soundings • Lightning-detection devices • Satellite thermal detection products (Modis, Landsat,Sentinel, MIROVA) • Webcams Current status: Katla • Unrest declared during the winter 2016 – quiet since then, except for occasional floods and gas release • No detectable increase rate in ground deformation Recurrence time of Katla’s eruptions since 1179 16 eruptions confirmed in historical records 100 1262- 100 Years 1357 since last 90 eruption! 80 1918-??? 70 60 On average every 49.3 years 50 Years 40 30 20 10 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Current status: Hekla • Monitored with extensive and multi- parametric network • It has shown very short precursory signals in past eruptions • Alert system has been setup for seismicity Current status: Hekla • Hekla is in an inflating phase since 2000. • The seismicity level is very low but it increases periodically. Current status: Bárðarbunga • 190 km long and up to 25 km wide • Last eruption in 2014- 2015 • With a vertical caldera collapse of 65m Current status: Bárðarbunga • Seismic activity since the end of the eruption – still ongoing with periodical large earthquakes • Signs of inflation from the GPS network • Indication of caldera floor uplift 20/02/2020 23 Current status: Bárðarbunga • Since the end of the eruption the deep seismicity started to increase between 2016-2018. The rate of the deep seismicity has been apparently increasing further since autumn 2018. • The deformation rate is slowing down (as shown well from KISA and VONC) stations. Since October-November 2018 the deformation has been flattening. • The gas did not show any significant changes between 2018- 2019. But the big difference in the gas composition (i.e. an increase in H2) occurred between 2016-2018. • Bárðarbunga is in recharging phase 24 Current status: Grímsvötn • One of the most frequently erupting volcanoes • It has shown quite regular trend between eruptions • We expect it will follow a similar trend before the next eruption, as well 20/02/2020 25 Current status: Grímsvötn 26 Current status: Öræfajökull • 3x4 km ice-filled caldera • 2000 m high • ~14km from the coastline (at the shortest) • ~ 257 km from Reykjavík • In 1362 VEI=6 and in 1727 VEI=4 27 Current status: Öræfajökull • Since September 2017 the volcanic unrest became clear • Aviation color code was changed to yellow and moved back to green in May 2018 28 Current status: Öræfajökull • Seismic and deformation (InSAR and GPS) data suggest that magma inflow is most likely still on-going but at a lower rate (since Oct-Nov 2018). • Geothermal fluids are still released from the system, but the gas concentration does not represent a health hazard. 29 Observation and estimation of plume height • The new VESPA system calculates automatically the hourly plume height and the MFR (http://brunnur.vedur.is/radar/vespa/) • Plume height on the hour is estimated as the mean, weighted by uncertainties, for all scans • Inversion for source parameters in the 1D PlumeMoM model using the radar plume height and vertical atmospheric profile from the ECMWF numerical weather prediction model Daily simulations of tephra dispersal A more flexible system to run the dispersal simulations has been developed to assimilate the newest data coming from the observational system: Daily results are available at dispersion.vedur.is Ash dispersal simulations Multiple simulations are produced on a daily basis for Öræfajökull: • 3 scenarios (6000m, 12000m, 24000m plume height) • 4 starting times a day (06, 12, 18, 24) Results available at: dispersion.vedur.is Thank you!.